Three more people have been arrested in connection with the Manchester concert attack as troops were deployed on to the streets of the UK after the government raised the terrorist threat level to critical for the first time since July 2007.

Greater Manchester police said on Wednesday they had arrested three men in south Manchester.

A neighbour at a property in south Manchester identified one of the men detained as Adel Forjani, in his mid-40s, whose grown-up son was also taken away, he said. Omar al-Faqhuri said the family were from Libya and had lived in the house for 15 years. On Wednesday afternoon, officers raided a flat on Granby Row, in Manchester city centre.

On Tuesday, police arrested a 23-year-old man in Chorlton, in the south of the city, near an address where the family of suspected bomber Salman Ramadan Abedi had previously lived. The home secretary, Amber Rudd, said it was likely Abedi had not acted alone.

After a meeting of the Cobra emergency committee, Rudd said 984 members of the armed forces were being deployed, initially in London but then elsewhere. A number of troops later arrived to take up positions at the Houses of Parliament.

The names of more of the 22 people killed in the attack emerged, taking to 12 the number of people who had been publicly identified. Friends Alison Howe and Lisa Lees were killed by the suicide bomber in the foyer of the Manchester Arena as they were waiting to collect their 15 year-old-daughters from the Ariana Grande concert. Their daughters survived.

Lee Hunter, Lisa Lees’s brother, wrote on Facebook: “For those who don’t know, Lisa is gone but never, ever forgotten.”

Jordan Howe confirmed his stepmother had died. “She was amazing to us all x love you loads Alison Howe,” he wrote on Facebook.

Martyn Hett, 29, who went missing after he became separated from friends at the concert, was also killed. Russell Hayward, believed to be Hett’s partner, said in a statement: “We got the news last night that our wonderful iconic and beautiful Martyn didn’t survive. He left this world exactly how he lived, centre of attention. I’m in a really bad way so please forgive if I don’t reply. Thankfully I have his wonderful family and amazing friends to keep each other strong. I love you Martyn. I always will X.”

Dennis Oliver, headteacher of Holmes Chapel comprehensive school, told the Express: “It has now been announced in the school that Nell has unfortunately died. I have just done six assemblies to tell the pupils. Children are all over the place crying. We are all devastated. The heart wrenches for me and everyone else.”

Nell had been on crutches but it is understood she had left them in the car to go and see Grande perform.

Jane Tweddle’s death was confirmed by the Blackpool school where she worked as a receptionist.

Jane Bailey, principal of South Shore Academy, said Tweddle, who was a mother of three, was “a truly wonderful friend and colleague”.

The Polish embassy in London confirmed that two Polish citizens had been killed: Angelika and Marcin Klis, aged 40 and 42 respectively. The Polish foreign minister, Witold Waszczykowski, said they had been waiting for their daughters at the arena.

Overnight, the families of 15-year-old Olivia Campbell and 32-year-old Kelly Brewster confirmed they had both died in the attack. On Tuesday the first victims to be named were 18-year-old Georgina Callander, eight-year-old Saffie Rose Roussos and 28-year-old John Atkinson.

Police say they now know the identities of those who died but formal naming may take up to five days.

Twenty people remain in “critical care” across Manchester, with people suffering from severe injuries including major organ damage and potential loss of limbs, Jon Rouse of the Greater Manchester Health and Social Care Partnership said.

Scotland Yard said soldiers would help guard Buckingham Palace, Downing Street, foreign embassies and the Palace of Westminster after the threat level was increased to critical on Tuesday night.

The Metropolitan police said there would be more stop-and-search and vehicle checkpoints. A Met statement said: “As a highly visible deterrent and disruptive tactic, officers will be making more use of stop-and-search, vehicle checkpoints and automatic number plate recognition technology.”

Rudd told Sky News “people are likely to see some military on the streets”. The move was intended to free up armed officers for counter-terrorism operations.

The extremist group Islamic State claimed responsibility for the attack on its messaging service, but there has been no evidence to support the claim.

Mark Rowley, the head of national counter-terrorism policing, said on Wednesday morning that police were conducting a number of searches to try to establish whether the suspected bomber worked alone or was part of a network.

He had probably travelled to Syria and had links with Isis, according to the French interior minister, Gérard Collomb, who told BFMTV that British investigators passed the informationto French authorities.

The Manchester police deputy chief constable, Ian Pilling, said the decision to up the threat level to critical would help the investigation into the attack. He said: “People across Greater Manchester have seen an increased police presence throughout the day and this will continue. They will be seen at key locations across the region.”

The Guardian understands that Abedi’s father, Abu Ismail Abedi, is thought to be in Tripoli.

The British-Libyan community in Manchester released a statement condemning the bombing as “an attack on all of us. Such depraved acts have no basis in Islam. All those responsible for senselessly destroying the lives of innocent people do not deserve to live in our community and should be behind bars. We support the police in bringing the perpetrators to justice, and in protecting the people of Manchester and the rest of the UK.”

Share This

We welcome comments that add information or perspective, and we encourage polite debate. If you log in with a social media account, your comment should appear immediately. If you prefer to remain anonymous, you may comment as a guest, using a name and an e-mail address of convenience. Your comment will be moderated.